Ionizing bars are used to generate positive and negative ions which may be used to eliminate built-up electrostatic charges on various items such as paper and/or plastic film products. Typically, when used to eliminate built-up electro-static charges on paper or plastic film products, long webs or sheets of the paper or plastic film product are passed over or under the ionizing bar in order to remove static charges. Due to the variation in width of a wide variety of paper and plastic film products, the width of the running webs and sheets varies from a few inches to several feet. As a result, a wide range of lengths of ionizing bars must be custom manufactured, usually on a short notice.
Numerous ionizing bar designs and production techniques have been described in the art, including those set forth in the following U.S. patents: D. Koerke U.S. Pat. No. 3,551,743; D. Simons, U.S. Pat. No. 3,585,448; M. Iosue, et al., U.S. Pat. No. 3,652,897; H. Richardson, et al., U.S. Pat. No. 3,875,461; A. Testone, U.S. Pat. No. 3,921,037; A. Testone, U.S. Pat. No. 3,968,405; A. Testone, U.S. Pat. No. 4,031,599; H. Bennecke U.S. Pat. No. 4,048,667; D. Simons, U.S. Pat. No. 4,216,518; A. Testone, U.S. Pat. No. 4,263,636; B. Metz, U.S. Pat. No. 4,271,451; D. Saureman, U.S. Pat. No. 4,498,116 and U.S. Pat. No. 4,502,091; K. Domschat, U.S. Pat. No. 5,034,651 and U.S. Pat. No. 5,057,966; W. Larkin, U.S. Pat. No. 5,501,899.
Certain known ionizing bars are comprised of a single elongated central high voltage electrode. The high voltage electrode is covered with an insulative or semiconductive sleeve and conductive sleeves. Emitter pins for generating the positive and negative ions extend outward from the electrode. In this type of known ionizing bar. a tubular metallic grounded housing surrounds the high voltage electrode. The metallic grounded housing includes an arrangement of cylindrical openings through which the emitter pins extend from the high voltage electrode.
Other prior art ionizing bars are comprised of a metal housing in the form of an elongated hollow metallic channel having a longitudinally extended opening. In this type of prior art ionizing bar, a high voltage electrode consisting of cable with an inner conductive core formed by a plurality of stranded wires is contained within the metallic channel of the housing. Emitter pins are formed on the outer layer of the cable by conductive paint.
Still other known ionizing bars include two or more parallel rows of metal electrodes with sharp emitter pins extending therefrom for generating, positive and negative ions on alternate rows.
Most of these prior art ionizing bars have a high voltage cable that is integral to the ionizing bar assembly and which is connected to a remotely-mounted high voltage power supply for providing power to the bar assembly. Second, although several of prior art ionizing bars do have connectors for removeably coupling a high voltage power supply to the ionizing bar, each of these connectors are located at only one end of the bar and are only suitable for a cable connection to the bar. Accordingly, a cable is coupled between the connector and the high voltage power supply. Additionally, in all of these prior art designs, the ionizing electrodes are located in a single row (positive and negative emitter pins alternating) or in two parallel rows with positive emitter pins arranged in parallel with negative emitter pins. Finally, in each of these designs all components of the bar, especially the housing, inner cables or bus rods. and insulators arc custom manufactured to a desired length.
Accordingly, it is would be desirable to provide an ionizing bar design which does not have a cable for connecting a high voltage power supply that is permanently hard-wired to the bar. Such a design should preferably include universal connectors at each end of the ionizing bar for coupling the bar directly to a power supply, or for coupling the ionizing bar to a power supply via a disconnectable extension cable. What is further needed is an ionizing bar design wherein the emitter pins are not arranged in a single row or in two parallel rows but are arranged in a more efficient configuration. What is further needed is a ioinizing bar design wherein multiple ionizing bars can be daisy chained together in order to achieve alternate lengths. Finally, what is needed is an ionizing bar design and a manufacturing method with would allow to pre-assemble a long ionizing bar assembly that will be ready to be cut to a customer-specified length and quickly shipped to the customer, rather that having to be custom assembled to a desired length.
The objective of this invention is to provide an ionizing bar that is, a) more reliable in operation, b) more economical and easy to manufacture, c) easy to connect to a high voltage power supply directly or via an extension cable, and d) a method of fabrication that provides shorter lead time to deliver bars to the customers.